The present invention relates to improvements in the field of laser printer toner cartridge repair and manufacture. Laser printer toner cartridges are manufactured to a high degree of precision, which precision is needed for proper operation and production of good printed image quality. With respect to some models of toner cartridges used in laser printers, original equipment manufacturers (OEM) include in the original cartridges structures and circuits that can detect the level of remaining toner. These structures typically include electrically conductive strips that function to conduct electrical signals from the cartridge hopper section of the cartridge regarding the level of remaining toner. When the OEM cartridges are repairs or remanufactured, the best known, if not only known way to assure that the laser printer will measure the toner level, and shut off automatically when the toner cartridge is empty is to leave the OEM toner supply tank electrically conductive seal strips in place. When the electrically charged strips, typically two in number, on either side of the open hopper tank are left in place, after the toner is replaced, these strips can trigger the printer's ability to stop printing when the hopper tank is empty of the replacement toner. However, such a process has its own set of problems, including problems relating to poor sealing of the cartridge after repair and until it has been installed in a printer, and problems associate with damage to the OEM strips. Thus, a need exists for structures and methods that can be used to repair or re-manufacture spent toner cartridges so that when refilled with toner, they are capable of operating to the same level of quality as a new, OEM cartridge.